Humans possess a remarkable ability to hold their breath. The pursuit of extended breath-holding has evolved into a competitive sport, showcasing the extraordinary limits to which the human body can adapt. Exploring these physiological adaptations and techniques reveals both the body’s resilience and the potential dangers involved.
The Current Breath-Holding Record
The current world record for static apnea, holding one’s breath without movement, has seen impressive advancements. As of June 14, 2025, Vitomir Maričić achieved a record of 29 minutes and 3 seconds with oxygen assistance. This surpasses the previous record of 24 minutes and 37.36 seconds, set by Budimir Šobat in 2021. Competitive breath-holding often involves pre-breathing techniques with pure oxygen to maximize oxygen stores.
The Body’s Response to Breath-Holding
When a person holds their breath, the body initiates involuntary physiological adjustments known as the mammalian dive reflex. One key component is bradycardia, where the heart rate significantly slows, conserving oxygen by reducing its demand and extending the available oxygen supply. Peripheral vasoconstriction also occurs, narrowing blood vessels in the extremities like arms and legs. This redirects blood flow and oxygen to vital organs such as the heart and brain.
Additionally, the spleen contracts, releasing a reserve of oxygenated red blood cells into the bloodstream, providing an extra boost of oxygen-carrying capacity. The primary trigger for the urge to breathe is a buildup of carbon dioxide (CO2) in the blood. As CO2 levels rise, the blood becomes more acidic, which the brain detects, signaling the body’s need to inhale. This physiological mechanism compels breathing before oxygen levels drop to dangerously low levels.
Techniques for Extending Breath-Hold Time
Freedivers and other breath-hold practitioners employ various methods to extend their time underwater. Mental preparation, including relaxation and visualization, plays a significant role in conserving oxygen and managing the urge to breathe. A calm mind reduces oxygen consumption, delaying the onset of discomfort from rising carbon dioxide levels.
Physical techniques also contribute to enhanced breath-hold capacity. “Lung packing” involves using the mouth and throat muscles to force additional air into the lungs beyond their normal capacity. This technique can increase lung volume by up to 25%, providing a larger initial oxygen reserve. Some individuals also train using CO2 tolerance tables, which gradually expose the body to increasing levels of carbon dioxide to extend the comfort period before the urge to breathe becomes overwhelming.
Hazards of Prolonged Breath-Holding
Prolonged breath-holding carries serious risks, particularly when practiced without supervision. One significant danger is shallow water blackout, a loss of consciousness caused by a lack of oxygen to the brain, often occurring in shallow water or upon ascent. This can happen when hyperventilation before a breath-hold unnaturally lowers carbon dioxide levels, delaying the urge to breathe until oxygen levels become critically low. Without the usual signal to breathe, a person can lose consciousness underwater and inhale water, leading to drowning.
Hypoxia, a deficiency of oxygen in the body’s tissues, and hypercapnia, an excess of carbon dioxide, are inherent to prolonged breath-holding. While the body has mechanisms to cope, severe exposure can lead to health issues. The body typically forces breathing before severe brain damage occurs during voluntary breath-holding out of water, but the risk of injury from fainting remains. Underwater, blackout almost invariably results in drowning. Therefore, breath-holding activities should never be attempted alone, and hyperventilation as a pre-breathing technique should be approached with extreme caution due to its potential to mask the body’s natural warning signs.